Thank you Marie and Rangeball.

I now realize that I haven't ever truely "shocked" my pool--ever . I will attempt to raise the FC to somewhere between 12-15 ppm this weekend. Once I get to that point, should I always maintain a steady FC range between 2-6 ppm since my cya averages between 25-30 ppm?

It is good to know that at least my pH and alk are in normal ranges. But, how do I double my calcium numbers?

I forgot to mention something I have noticed this entire swim season that leaves me clueless. On the deep end of my pool I have a retaining wall that has carter stone mortered on for decoration. It is basically a mini cliff for the kids to jump off of instead of a diving board. Anyway, the tile on the deep end has white stuff all over it and it doesn't seem to want to be scraped off with my nails or the pool brush. Is it calcium? This white stuff on tile is only on the deep end tile, below the mortered stone wall.

Thanks again,
Shannon